Several problems spring to mind. Firstly, trees (and that is what a spruce is, even if it is dwarf) do not want their roots buried any deeper by covering with soil, even a few inches. Secondly, trees can impoverish and dry out the surrounding soil and only certain plants adapted to the conditions will thrive there. Thirdly, the herbs you name need full sun and will not be happy under a tree. Basically the tree will adversely affect the herbs, not the other way round.

Thanks for the response.

It's small enough that it's going to minimally shade any plants, especially south facing side. When it gets bigger I may need to rearrange things. I think I'll give it a shot though.

You missed part of what flora was warning you about. Woody trees and shrubs do not like having their root systems disturbed, either by adding more soil or by doing a lot of digging around the roots.